--- /dev/null
+\font\musicfnt=musix20
+\def\mb#1{{\musicfnt\musicfnt\char#1}}
+\newdimen\wid
+\newdimen\inc
+\newdimen\here
+\def\hruler#1{%
+ \wid=#1pt
+ \inc=\wid
+ \divide\inc by #1
+ \divide\wid by 2
+ \here=-\wid
+ \loop\ifdim\here<\wid\advance\here by\inc
+ \hbox to0pt{\kern\here\vrule width0.05pt height 2pt\hss}%
+ \repeat%
+}
+\def\vruler#1{%
+ \wid=#1pt
+ \inc=\wid
+ \divide\inc by #1
+ \divide\wid by 2
+ \here=-\wid
+ \loop\ifdim\here<\wid\advance\here by\inc
+ \vbox to0pt{\vskip\here\vrule width2pt height 0.05pt\vss}%
+ \repeat%
+}
+\def\twhrul{\hbox to 0pt{\hbox{\hruler{20}\vrule
+ width0.1pt height 3ptdepth 1pt}}}
+\def\twvrul{\hbox{\vbox to 20pt{\vruler{20}\vrule
+ width3pt height 0.1pt}}}
+
+\def\doitem#1{
+ #1 %
+ %\twvrul%doesn't work
+ \hbox to 50pt{\qquad\twhrul\mb{#1}\hss}\setbox0=\hbox{\mb{#1}} width \the\wd0\ depth \the\dp0 \ height \the\ht0}
+
+\newcount\n
+\def\charn{\n=0
+ \loop\ifnum\n<255\advance\n by1
+ \doitem{\number\n}\endgraf\repeat}
+
+
+ \charn
+
+
+
+
+
+
+\bye
\ No newline at end of file